1. Field
The present invention is generally related to keyboards, and more particularly, to an ergonomic and adjustable computer keyboard.
2. Description of the Related Art
Origins of the Typewriter and Numeric Keypad
As is generally known in the field, the typewriter was invented in the late 1800's. What is less well known is that in the early 1900's, the rapid pace of industrial innovation led to credible attempts at improving the typewriter keyboard, including splitting it into right and left segments (e.g. McNamara, 1921 and Tyberg, 1926) and streamlining the layout of the keys (and Dvorak, 1936). However, in spite of the numerous improvements invented in this time period, the commercial typewriter became standardized on the less effective Sholes' design without substantial changes to its geometry or the organization of the keys.
The static design of the typewriter was probably due in part to the rapidly established dependence of both workers and employers on standardized, and “portable” methods and equipment for written communications. Even though it was far from optimal by modern standards, the typewriter was a powerful productivity tool compared to writing longhand. It took substantial practice and skill to become proficient using a typewriter (in part because of its non-optimal design), and when students and job trainees attained proficiency, there were powerful social and economic forces resisting any changes that would have required retraining. Another phenomenon that retarded keyboard evolution in this period was the mechanical complexity of the devices. The equipment was limited by inflexible mechanical constraints.
The numeric keypad, which is an important part of the now-traditional computer keyboard, experienced an evolutionary path independent of the typewriter (see http://www.hamiltonsundstrandcorp.com/hsc/details/0,3797,CLI1_DIV22_ETI3212,00. html)
Perhaps because of the more diverse uses to which this type of device was subjected, or because it was simpler to learn and use a variety of configurations, or because some models were highly effective for specialized tasks, numeric keypads (adding machines) were produced in a variety of layouts through the early 1900s (see, e.g., http://www.webcom.com/calc/). The invention of the compact 10-key adding machine dates to 1914 (patented by David Sunstrand, see http://www.hamiltonsundstrandcorp.com/hsc/details/0,3797,CLI1_DIV22_ET13212,00. html, but much larger adding machines with far more keys (with columns of numbers dedicated to each decimal position) were in use even into the 1970's (see http://www.tfh-berlin.de/˜hamann/history/).
Computer Keyboards
The first computer terminal keyboards used the same typewriter-style arrangement of keys which had been adopted by earlier teletype machines, except for the addition of several new key actions which had not existed on the typewriter. Even with the invention of the personal computer, still more new key actions were simply added to the perimeter without changing the core typewriter-style layout. The first significant change to the keyboard occurred in 1983 with the introduction of a second-generation personal computer, the IBM XT, when the numeric keypad was added to the right side of the keyboard.
The second significant change to the keyboard was in 1986, coincident with the rapidly spreading usage of computers by the majority or office workers and the need for faster on-screen editing and navigation. New dedicated editing and navigational keys were added between the typewriter section and the numeric keypad section, making these new keyboards significantly wider still than their predecessors. This new version of the keyboard was called “enhanced” or “extended,” and has become the de facto standard for virtually all computers. For the purposes of this discussion, this enhanced/extended keyboard design will be called the “traditional” computer keyboard.
Evolution of Computer Mousing
Douglas Englebart invented the computer mouse in 1968 and patented it in 1970 (see U.S. Pat. No. 3,541,541). However, it wasn't until the introduction of the first APPLE® computer in the 1980's that the computer mouse became an important medium for interacting with computers. And it wasn't until the introduction by MICROSOFT® in the 1990'S of the first WINDOWS®-based graphical user interface, after the evolution of the current “traditional” keyboard, that a majority of computer users began to be increasingly dependent on the mouse in their computer work.
Increasing dependence on the mouse created problems with the wide traditional computer keyboard. Since most people are right-handed, most computer users with wide traditional keyboards are forced to do extensive precision pointing and clicking while the right arm is extended beyond the right side of the keyboard. With the long-standard key spacing of 0.75 inch, the alphanumeric section of keys is approximately 11 inches wide, while the total width of a traditional computer keyboard is ˜19 inches or more. Because all the non-alpha additions to the traditional typewriter keyboard are to the right side, the right side of the traditional keyboard is approximately 18 inches from the center of the alpha keys (effectively 36 inches in total width). Assuming a typical adult shoulder width of 16 to 20 inches, the average right-handed user (˜80% of the population) would have to reach for the mouse approximately 8-9 inches farther out than the ideal front-of-shoulder location.
Alternative Computer Keyboards
Alternative computer (electronic) keyboard designs began appearing in the patent and scientific literature as early as 1964, some long before the invention of the personal computer (IBM, 1964; Kroemer, 1972; Einbinder 1975; Malt and Hobday 1982; Zipp et al., 1983; McCall, 1983; Nakeseko et al, 1985; Lahr, 1987). Zip et al. in 1983 documented some of the features associated with ergonomic keyboards. For example, they documented that a semi-split keyboard (with a center-back, vertically-oriented pivot point) optimally should have a front-opening range up to approximately 30 degrees; and that tenting is optimal in the range of 10 to 20 degrees, while tenting beyond 20 degrees would cause detrimental effects for most users and tenting less than 10 degrees would not provide maximal relaxation of the forearm muscles.
McCall and Lahr described fully-split keyboards mounted on the edge of a desk or to the arms of a chair. Lahr also described a measurement feature for quantitatively determining the position and orientation of the keying modules.
The first known commercial alternative keyboard was the Maltron keyboard, a fixed-split design with semi-concave key arrays, and with isolated thumb-operated keypads near the midline of the keyboard, which was produced and sold in the United Kingdom in the mid-1980s. The first known commercial letter-based alternative keyboard in the U.S. was the KINESIS® CONTOURED™ keyboard (similar to the Maltron), introduced in 1992. This was followed by the introduction of the Comfort keyboard (a fully-adjustable split keyboard mounted on a long desktop track) in late 1992 and the APPLE® semi-adjustable keyboard (two conventional keying modules linked by center-rear pivot point, with loosely-associated plastic palm rests), in early 1993.
Many of the published designs of the 1970's and 1980's (Kroemer, 1972; Einbinder, 1975; and Nakeseko et al., 1985) disclose partially split keyboards with right and left halves rotated to a fixed orientation around a pivot point near the center rear of the keyboard. Sometimes the center of the keyboard was tented slightly.
Some keyboard designs commercialized in the 1990's recognized the importance of combining separation, tenting, and palm rests with a narrow, largely symmetrical shape so the mouse could be positioned more or less directly in front of the shoulder (e.g., the fixed-split CONTOURED™ keyboard from Kinesis Corporation, and fixed or adjustable semi-split keyboards from Cherry Electrical Products, Fujitsu-Siemens, and Acer).
The biggest problem with alternative keyboard designs has been achieving a balance of effectiveness (for both comfort and productivity), ease of use (setup and adjustment), familiarity (standard key layout), general appearance, adaptation (minimal or no learning curve), and cost. Historically, more-effective products have had more features and more exotic features and typically have required greater adaptation time. This, in turn, has reduced acceptance. For any two products with equivalent effectiveness, the one which is easier to set up and use with reproducible settings will be preferred as well.
Accordingly, there is a need for a keyboard that is user-adjustable for providing a more comfortable keying position, accommodating reproducible position settings, and increasing adaptability and productivity while being easy to manufacture and operate.